1X6 THE HISTORY OF BIOLOGY 



question has naturally been of only indirect importance to biology, which 

 deals mostly with the material phenomena of life, but all the same it has 

 had its influence on many purely biological problems and therefore cannot 

 be entirely neglected here. 



It was just in this sphere of science that Cartesianism experienced the 

 strongest opposition on the part of such scientists as did not accept Aris- 

 totle's views. In France it was Pierre Gassendi (1591-1655) who stands out 

 most conspicuously as the opponent of Descartes. He was born of poor par- 

 ents, but rose to high dignities in the Catholic Church. As a philosopher he 

 sought to revive the ancient atomic theory and wrote a defence of Epicurus, 

 who in the Middle Ages was the object of universal execration. Against 

 Descartes he argued that his conclusion that thought was a proof of exist- 

 ence was incapable of realization. For the rest, Gassendi was a great admirer 

 of Galileo for his discoveries in the realm of physics, which he partly im- 

 proved upon; being a priest, however, he was forced to deny the Coperni- 

 can cosmic system. He conceived warmth to be the soul in existence. The 

 relation between matter and human consciousness he tried to explain in the 

 same way as Lucretius, but he admitted that there were insoluble difficulties 

 in the way; besides, as a priest he had of course to maintain the existence 

 of an immortal soul. 



Another thinker who held a markedly mechanical view of existence was 

 the Englishman Thomas Hobbes. He had studied in Oxford and travelled a 

 great deal in Europe, and afterwards spent the greater part of his long life 

 as a private scholar. He died in 1679 ^^ ^^^ ^E>^ ^^ ninety-one. He regarded 

 all that happens as motion; mental impressions were in his view motions in 

 the nervous system, which arose as a reaction to motions in the external 

 world. Hobbes speculated most, however, upon problems of ethics and states- 

 manship; he had no interest in biology. 



The same may be said of another philosopher, who nevertheless, curi- 

 ously enough, came to play a not unimportant part in the history of biology 

 — Baruch Spinoza. Born of Jewish parents at Amsterdam in 1631, he was 

 brought up to become a rabbi, but as he failed to follow the teachings of 

 the synagogue, he was excommunicated and afterwards lived in the closest 

 retirement, making a livelihood by polishing eye-glasses, until the time of 

 his death, in 1677. Only a few liberal-minded people dared during his life- 

 time to acknowledge acquaintance with the outcast, and although in some 

 respects he was highly admired, it was not until later that his writings won 

 any general acceptance. He himself, thanks undoubtedly to his mild and un- 

 assuming temperament and his retired life, escaped falling a victim to the 

 religious fanaticism of the age, for even in Holland, which was a compara- 

 tively liberal-minded country, tolerance towards heterodox persons was a 

 rare thing in those days. 



